1. Field of the Invention
This invention relates to a planing machine, particularly to one provided with a tool-shaft locking device.
2. Description of the Prior Art
A conventional planing machine generally has a tool shaft on the machine base, and the tool shaft is provided with a planing knife, which is rotated together with the tool-shaft for planing a work. FIG. 1 shows a conventional planing machine, which includes a tool-shaft 10, a belt wheel 21 fixed on one end of the tool-shaft 10, an endless belt 20 extending around the belt wheel 21 and also around an belt wheel fixed on a spindle of a motor 21. Further, a plate cover 11 is fixed on a shaft body 13, with a planing knife 14 sandwiched between the plate cover 11 and the shaft body 13 by means of bolts. In case the planing knife 14 is needed to be adjusted vertically in its position on the shaft body 13, the bolts 12 have to be loosened first before the planing knife 14 can be moved up or down relative to the shaft body 13. Then the bolts 12 are to be screwed tightly again to lock the planing knife 14 at the adjusted position.
However, the shaft body 13 can rotate in adjusting process of the planing knife 14, so the belt wheel 21 has to be held tightly with one hand, and the planing knife 14 is to be held with the other hand for adjusting. Therefore, there is a potential danger of hurting the other hand in adjusting the sharp planing knife 14, causing inconvenience in using the conventional planing machine.